The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
In data processing, data storage systems may manage access to user or application data stored as blocks of data on data storage devices. Data storage systems maintain location metadata identifying the location of user or application data for various purposes, such as for retrieving, storing, or updating the user or application data, properly associating other non-location metadata with the user or application data, cloning the user or application data, and as a part of system snapshots that captures the state of the user or application data at particular times. Traditional data storage systems may identify the location of user or application data or other non-location metadata by storing pointers to the physical block address of the user or application data or other non-location metadata.
In some data storage systems, data or metadata may frequently be re-located to new locations, such as to different storage units. For example, a storage administrator that administrates the storage of user or application data in a virtual data center may need to relocate certain data or metadata stored on one storage unit to a different storage unit of the virtual data center for many possible reasons, relating to but not limited to service level management of performance, data availability, system maintenance, error recovery, failure recovery, cost optimization, load balancing, and capacity management. Furthermore, a storage controller that administrates data and metadata stored in cloud computing and virtual data center environments may be able to obtain further storage units with ease and, thus, may move data and metadata even more frequently in such environments. In order to properly serve their function, data storage system records need to reflect the up-to-date location of data. Maintaining accurate data location records can be a cumbersome task in systems where data locations change frequently. New techniques for alleviating the burden of data location changes on data storage systems are needed.